package com.lgy.ms.core.utils;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import org.xml.sax.InputSource;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.StringReader;
import java.math.BigInteger;


/**
 * Implementation of MIME's Base64 encoding and decoding conversions.
 * Optimized code. (raw version taken from oreilly.jonathan.util, 
 * and currently com.sun.org.apache.xerces.internal.ds.util.Base64)
 *
 * @author Raul Benito(Of the xerces copy, and little adaptations).
 * @author Anli Shundi
 * @author Christian Geuer-Pollmann
 * @see <A HREF="ftp://ftp.isi.edu/in-notes/rfc2045.txt">RFC 2045</A>
 */
public class Base64 {

   /** {@link java.util.logging} logging facility */
    static java.util.logging.Logger log = 
        java.util.logging.Logger.getLogger(Base64.class.getName());


   /** Field BASE64DEFAULTLENGTH */
   public static final int BASE64DEFAULTLENGTH = 76;

   /** Field _base64length */
   static int _base64length = Base64.BASE64DEFAULTLENGTH;

   private Base64() {
     // we don't allow instantiation
   }



   /**
    * Method decodeBigIntegerFromElement
    *
    * @param element
    * @return the biginter obtained from the node
    * @throws Exception
    */
   public static BigInteger decodeBigIntegerFromElement(Element element) throws Exception
   {
      return new BigInteger(1, Base64.decode(element));
   }

   /**
    * Method decodeBigIntegerFromText
    *
    * @param text
    * @return the biginter obtained from the text node
    * @throws Exception
    */
   public static BigInteger decodeBigIntegerFromText(Text text) throws Exception
   {
      return new BigInteger(1, Base64.decode(text.getData()));
   }


   /**
    * Method decode
    *
    * Takes the <CODE>Text</CODE> children of the Element and interprets
    * them as input for the <CODE>Base64.decode()</CODE> function.
    *
    * @param element
    * @return the byte obtained of the decoding the element
    * $todo$ not tested yet
    * @throws Exception
    */
   public static byte[] decode(Element element) throws Exception {

      Node sibling = element.getFirstChild();
      StringBuffer sb = new StringBuffer();

      while (sibling!=null) {
         if (sibling.getNodeType() == Node.TEXT_NODE) {
            Text t = (Text) sibling;

            sb.append(t.getData());
         }
         sibling=sibling.getNextSibling();
      }

      return decode(sb.toString());
   }


   /**
    * Method decode
    *
    *
    * @param base64
    * @return the UTF bytes of the base64
    * @throws Exception
    *
    */
   public static byte[] decode(byte[] base64) throws Exception  {   	   
         return decodeInternal(base64);
   }



   /**
    * Encode a byte array and fold lines at the standard 76th character.
    *
    * @param binaryData <code>byte[]<code> to be base64 encoded
    * @return the <code>String<code> with encoded data
    */
   public static String encode(byte[] binaryData) {
        return encode(binaryData,BASE64DEFAULTLENGTH);
   }

   /**
    * Method main
    *
    *
    * @param args
    *
    * @throws Exception
    */
   public static void main(String[] args) throws Exception {

      DocumentBuilderFactory docBuilderFactory =
         DocumentBuilderFactory.newInstance();
      DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
      String testString1 =
         "<container><base64 value=\"Should be 'Hallo'\">SGFsbG8=</base64></container>";
      InputSource inputSource = new InputSource(new StringReader(testString1));
      Document doc = docBuilder.parse(inputSource);
      Element base64Elem =
         (Element) doc.getDocumentElement().getChildNodes().item(0);

      System.out.println(new String(decode(base64Elem)));
   }
   static private final int  BASELENGTH         = 255;
   static private final int  LOOKUPLENGTH       = 64;
   static private final int  TWENTYFOURBITGROUP = 24;
   static private final int  EIGHTBIT           = 8;
   static private final int  SIXTEENBIT         = 16;
   static private final int  FOURBYTE           = 4;
   static private final int  SIGN               = -128;
   static private final char PAD                = '=';
   static private final boolean fDebug          = false;
   static final private byte [] base64Alphabet        = new byte[BASELENGTH];
   static final private char [] lookUpBase64Alphabet  = new char[LOOKUPLENGTH];

   static {

       for (int i = 0; i<BASELENGTH; i++) {
           base64Alphabet[i] = -1;
       }
       for (int i = 'Z'; i >= 'A'; i--) {
           base64Alphabet[i] = (byte) (i-'A');
       }
       for (int i = 'z'; i>= 'a'; i--) {
           base64Alphabet[i] = (byte) ( i-'a' + 26);
       }

       for (int i = '9'; i >= '0'; i--) {
           base64Alphabet[i] = (byte) (i-'0' + 52);
       }

       base64Alphabet['+']  = 62;
       base64Alphabet['/']  = 63;

       for (int i = 0; i<=25; i++)
           lookUpBase64Alphabet[i] = (char)('A'+i);

       for (int i = 26,  j = 0; i<=51; i++, j++)
           lookUpBase64Alphabet[i] = (char)('a'+ j);

       for (int i = 52,  j = 0; i<=61; i++, j++)
           lookUpBase64Alphabet[i] = (char)('0' + j);
       lookUpBase64Alphabet[62] = '+';
       lookUpBase64Alphabet[63] = '/';

   }

   protected static final boolean isWhiteSpace(byte octect) {
       return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
   }

   protected static final boolean isPad(byte octect) {
       return (octect == PAD);
   }


   /**
    * Encodes hex octects into Base64
    *
    * @param binaryData Array containing binaryData
    * @return Encoded Base64 array
    */
   /**
    * Encode a byte array in Base64 format and return an optionally
    * wrapped line.
    *
    * @param binaryData <code>byte[]</code> data to be encoded
    * @param length <code>int<code> length of wrapped lines; No wrapping if less than 4.
    * @return a <code>String</code> with encoded data
    */
    public static String encode(byte[] binaryData,int length) {
        
    	if (length<4) {
    		length=Integer.MAX_VALUE;
        }

       if (binaryData == null)
           return null;

       int      lengthDataBits    = binaryData.length*EIGHTBIT;
       if (lengthDataBits == 0) {
           return "";
       }
       
       int      fewerThan24bits   = lengthDataBits%TWENTYFOURBITGROUP;
       int      numberTriplets    = lengthDataBits/TWENTYFOURBITGROUP;
       int      numberQuartet     = fewerThan24bits != 0 ? numberTriplets+1 : numberTriplets;
       int      quartesPerLine    = length/4;
       int      numberLines       = (numberQuartet-1)/quartesPerLine;
       char     encodedData[]     = null;

       encodedData = new char[numberQuartet*4+numberLines];

       byte k=0, l=0, b1=0,b2=0,b3=0;

       int encodedIndex = 0;
       int dataIndex   = 0;
       int i           = 0;
       if (fDebug) {
           System.out.println("number of triplets = " + numberTriplets );
       }

       for (int line = 0; line < numberLines; line++) {
           for (int quartet = 0; quartet < 19; quartet++) {
               b1 = binaryData[dataIndex++];
               b2 = binaryData[dataIndex++];
               b3 = binaryData[dataIndex++];

               if (fDebug) {
                   System.out.println( "b1= " + b1 +", b2= " + b2 + ", b3= " + b3 );
               }

               l  = (byte)(b2 & 0x0f);
               k  = (byte)(b1 & 0x03);

               byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);

               byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);
               byte val3 = ((b3 & SIGN)==0)?(byte)(b3>>6):(byte)((b3)>>6^0xfc);

               if (fDebug) {
                   System.out.println( "val2 = " + val2 );
                   System.out.println( "k4   = " + (k<<4));
                   System.out.println( "vak  = " + (val2 | (k<<4)));
               }

               encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
               encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
               encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ];
               encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ];

               i++;
           }           
           	encodedData[encodedIndex++] = 0xa;           
       }

       for (; i<numberTriplets; i++) {
           b1 = binaryData[dataIndex++];
           b2 = binaryData[dataIndex++];
           b3 = binaryData[dataIndex++];

           if (fDebug) {
               System.out.println( "b1= " + b1 +", b2= " + b2 + ", b3= " + b3 );
           }

           l  = (byte)(b2 & 0x0f);
           k  = (byte)(b1 & 0x03);

           byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);

           byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);
           byte val3 = ((b3 & SIGN)==0)?(byte)(b3>>6):(byte)((b3)>>6^0xfc);

           if (fDebug) {
               System.out.println( "val2 = " + val2 );
               System.out.println( "k4   = " + (k<<4));
               System.out.println( "vak  = " + (val2 | (k<<4)));
           }

           encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ];
       }

       // form integral number of 6-bit groups
       if (fewerThan24bits == EIGHTBIT) {
           b1 = binaryData[dataIndex];
           k = (byte) ( b1 &0x03 );
           if (fDebug) {
               System.out.println("b1=" + b1);
               System.out.println("b1<<2 = " + (b1>>2) );
           }
           byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ k<<4 ];
           encodedData[encodedIndex++] = PAD;
           encodedData[encodedIndex++] = PAD;
       } else if (fewerThan24bits == SIXTEENBIT) {
           b1 = binaryData[dataIndex];
           b2 = binaryData[dataIndex +1 ];
           l = ( byte ) ( b2 &0x0f );
           k = ( byte ) ( b1 &0x03 );

           byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0);
           byte val2 = ((b2 & SIGN)==0)?(byte)(b2>>4):(byte)((b2)>>4^0xf0);

           encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )];
           encodedData[encodedIndex++] = lookUpBase64Alphabet[ l<<2 ];
           encodedData[encodedIndex++] = PAD;
       }

       //encodedData[encodedIndex] = 0xa;
       
       return new String(encodedData);
   }

   /**
    * Decodes Base64 data into octects
    *
    * @param encoded Byte array containing Base64 data
    * @return Array containind decoded data.
    * @throws Exception
    */
   public final static byte[] decode(String encoded) throws Exception {

       if (encoded == null)
           return null;

       return decodeInternal(encoded.getBytes());
   }
   protected final static byte[] decodeInternal(byte[] base64Data) throws Exception {
       // remove white spaces
       int len = removeWhiteSpace(base64Data);
       
       if (len%FOURBYTE != 0) {
           throw new Exception("decoding.divisible.four");
           //should be divisible by four
       }

       int      numberQuadruple    = (len/FOURBYTE );

       if (numberQuadruple == 0)
           return new byte[0];

       byte     decodedData[]      = null;
       byte     b1=0,b2=0,b3=0, b4=0;


       int i = 0;
       int encodedIndex = 0;
       int dataIndex    = 0;
       
       //decodedData      = new byte[ (numberQuadruple)*3];
       dataIndex=(numberQuadruple-1)*4;
       encodedIndex=(numberQuadruple-1)*3;
       //first last bits.
       b1 = base64Alphabet[base64Data[dataIndex++]];
       b2 = base64Alphabet[base64Data[dataIndex++]];
       if ((b1==-1) || (b2==-1)) {
                throw new Exception("decoding.general");//if found "no data" just return null
        }

        
        byte d3,d4;
        b3 = base64Alphabet[d3=base64Data[dataIndex++]];
        b4 = base64Alphabet[d4=base64Data[dataIndex++]];
        if ((b3==-1 ) || (b4==-1) ) {
        	//Check if they are PAD characters
            if (isPad( d3 ) && isPad( d4)) {               //Two PAD e.g. 3c[Pad][Pad]
                if ((b2 & 0xf) != 0)//last 4 bits should be zero
                        throw new Exception("decoding.general");
                decodedData = new byte[ encodedIndex + 1 ];                
                decodedData[encodedIndex]   = (byte)(  b1 <<2 | b2>>4 ) ;                
            } else if (!isPad( d3) && isPad(d4)) {               //One PAD  e.g. 3cQ[Pad]                
                if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
                        throw new Exception("decoding.general");
                decodedData = new byte[ encodedIndex + 2 ];                
                decodedData[encodedIndex++] = (byte)(  b1 <<2 | b2>>4 );
                decodedData[encodedIndex]   = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );                
            } else {
                throw new Exception("decoding.general");//an error  like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
            }
        } else {
            //No PAD e.g 3cQl
            decodedData = new byte[encodedIndex+3];
            decodedData[encodedIndex++] = (byte)(  b1 <<2 | b2>>4 ) ;
            decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );
            decodedData[encodedIndex++] = (byte)( b3<<6 | b4 );
        }
        encodedIndex=0;
        dataIndex=0;
       //the begin
       for (i=numberQuadruple-1; i>0; i--) {
    	   b1 = base64Alphabet[base64Data[dataIndex++]];
           b2 = base64Alphabet[base64Data[dataIndex++]];
           b3 = base64Alphabet[base64Data[dataIndex++]];
           b4 = base64Alphabet[base64Data[dataIndex++]];

           if ( (b1==-1) ||
        		(b2==-1) ||
        		(b3==-1) ||
        		(b4==-1) ) {        	  
        	   throw new Exception("decoding.general");//if found "no data" just return null   
           }
                       
           decodedData[encodedIndex++] = (byte)(  b1 <<2 | b2>>4 ) ;
           decodedData[encodedIndex++] = (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) );
           decodedData[encodedIndex++] = (byte)( b3<<6 | b4 );
       }            
       return decodedData;
   }
   
   /**
    * Decodes Base64 data into  outputstream
    *
    * @param base64Data Byte array containing Base64 data
    * @param os the outputstream
    * @throws IOException
    * @throws Exception
    */
   public final static void decode(byte[] base64Data,
        OutputStream os) throws Exception, IOException {	    
    // remove white spaces
    int len = removeWhiteSpace(base64Data);
    
    if (len%FOURBYTE != 0) {
        throw new Exception("decoding.divisible.four");
        //should be divisible by four
    }

    int      numberQuadruple    = (len/FOURBYTE );

    if (numberQuadruple == 0)
        return;

    //byte     decodedData[]      = null;
    byte     b1=0,b2=0,b3=0, b4=0;

    int i = 0;

    int dataIndex    = 0;    
    
    //the begin
    for (i=numberQuadruple-1; i>0; i--) {
    	b1 = base64Alphabet[base64Data[dataIndex++]];
        b2 = base64Alphabet[base64Data[dataIndex++]];
        b3 = base64Alphabet[base64Data[dataIndex++]];
        b4 = base64Alphabet[base64Data[dataIndex++]];
        if ( (b1==-1) ||
        	(b2==-1) ||
        	(b3==-1) ||
        	(b4==-1) )
         throw new Exception("decoding.general");//if found "no data" just return null

        

        os.write((byte)(  b1 <<2 | b2>>4 ) );
        os.write((byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
        os.write( (byte)( b3<<6 | b4 ));
    }   
    b1 = base64Alphabet[base64Data[dataIndex++]];
    b2 = base64Alphabet[base64Data[dataIndex++]];
    
    //  first last bits.
    if ((b1==-1) ||
        (b2==-1) ){
             throw new Exception("decoding.general");//if found "no data" just return null
     }

     byte d3,d4;
     b3= base64Alphabet[d3 = base64Data[dataIndex++]];
     b4= base64Alphabet[d4 = base64Data[dataIndex++]];
     if ((b3==-1 ) ||
          (b4==-1) ) {//Check if they are PAD characters
         if (isPad( d3 ) && isPad( d4)) {               //Two PAD e.g. 3c[Pad][Pad]
             if ((b2 & 0xf) != 0)//last 4 bits should be zero
                     throw new Exception("decoding.general");                             
             os.write( (byte)(  b1 <<2 | b2>>4 ) );                
         } else if (!isPad( d3) && isPad(d4)) {               //One PAD  e.g. 3cQ[Pad]             
             if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
                     throw new Exception("decoding.general");                            
             os.write( (byte)(  b1 <<2 | b2>>4 ));
             os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));                
         } else {
             throw new Exception("decoding.general");//an error  like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
         }
     } else {
         //No PAD e.g 3cQl         
         os.write((byte)(  b1 <<2 | b2>>4 ) );
         os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
         os.write((byte)( b3<<6 | b4 ));
     }
    return ;
   }
   
   /**
    * Decodes Base64 data into  outputstream
    *
    * @param is containing Base64 data
    * @param os the outputstream
    * @throws IOException
    * @throws Exception
    */
   public final static void decode(InputStream is,
        OutputStream os) throws Exception, IOException {
	//byte     decodedData[]      = null;
    byte     b1=0,b2=0,b3=0, b4=0;    

    int index=0;
    byte []data=new byte[4];
    int read;
    //the begin
    while ((read=is.read())>0) {
        byte readed=(byte)read;
    	if (isWhiteSpace(readed)) {
    		continue;
        }
        if (isPad(readed)) {
            data[index++]=readed;
            if (index==3)
                data[index++]=(byte)is.read();
            break;   
        }
        
        
        if ((data[index++]=readed)==-1) {
            throw new Exception("decoding.general");//if found "no data" just return null
           } 
        
        if (index!=4) {
        	continue;
        }
        index=0;
        b1 = base64Alphabet[data[0]];
        b2 = base64Alphabet[data[1]];
        b3 = base64Alphabet[data[2]];
        b4 = base64Alphabet[data[3]];

        os.write((byte)(  b1 <<2 | b2>>4 ) );
        os.write((byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
        os.write( (byte)( b3<<6 | b4 ));
    }       
    

    byte     d1=data[0],d2=data[1],d3=data[2], d4=data[3];
    b1 = base64Alphabet[d1];
    b2 = base64Alphabet[d2];
    b3 = base64Alphabet[ d3 ];
    b4 = base64Alphabet[ d4 ];
     if ((b3==-1 ) ||
         (b4==-1) ) {//Check if they are PAD characters
         if (isPad( d3 ) && isPad( d4)) {               //Two PAD e.g. 3c[Pad][Pad]
             if ((b2 & 0xf) != 0)//last 4 bits should be zero
                     throw new Exception("decoding.general");                             
             os.write( (byte)(  b1 <<2 | b2>>4 ) );                
         } else if (!isPad( d3) && isPad(d4)) {               //One PAD  e.g. 3cQ[Pad]
             b3 = base64Alphabet[ d3 ];
             if ((b3 & 0x3 ) != 0)//last 2 bits should be zero
                     throw new Exception("decoding.general");                            
             os.write( (byte)(  b1 <<2 | b2>>4 ));
             os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));                
         } else {
             throw new Exception("decoding.general");//an error  like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data
         }
     } else {
         //No PAD e.g 3cQl         
         
         os.write((byte)(  b1 <<2 | b2>>4 ) );
         os.write( (byte)(((b2 & 0xf)<<4 ) |( (b3>>2) & 0xf) ));
         os.write((byte)( b3<<6 | b4 ));
     }
    
    return ;
   }
   /**
    * remove WhiteSpace from MIME containing encoded Base64 data.
    * 
    * @param data  the byte array of base64 data (with WS)
    * @return      the new length
    */
   protected static int removeWhiteSpace(byte[] data) {
       if (data == null)
           return 0;

       // count characters that's not whitespace
       int newSize = 0;
       int len = data.length;
       for (int i = 0; i < len; i++) {
           byte dataS=data[i];
           if (!isWhiteSpace(dataS))
               data[newSize++] = dataS;
       }
       return newSize;
   }
}
